Influence of Tunnel Lining Design Parameters on Construction Carbon Emissions

2021 ◽  
pp. 185-221
Author(s):  
Chun Guo ◽  
Jianfeng Xu
Keyword(s):  
Carbon Emissions ◽  
Tunnel Lining ◽  
Design Parameters ◽  
Tunnel Lining Design

scholarly journals Nonlinear subgrade reaction solution for circular tunnel lining design based on mobilized strength of undrained clay

2018 ◽  
Vol 55 (2) ◽  
pp. 155-170 ◽  
Author(s):  
Dong-ming Zhang ◽  
Kok-Kwang Phoon ◽  
Qun-fang Hu ◽  
Hong-wei Huang
Keyword(s):  
Design Method ◽  
Large Strain ◽  
Tunnel Lining ◽  
Subgrade Reaction ◽  
Circular Tunnel ◽  
Nonlinear Solution ◽  
Reaction Solution ◽  
Tunnel Convergence ◽  
Tunnel Lining Design ◽  
Internal Forces

This paper presents a nonlinear solution of a radial subgrade reaction–displacement (pk–ur) curve for circular tunnel lining design in undrained clay. With the concept of soil shear strength nonlinearly mobilized with shear strain, an analytical solution of pk is obtained using the mobilized strength design method. Two typical deformation modes are considered, namely oval and uniform. A total of 197 orthogonally designed cases are used to calibrate the proposed nonlinear solution of pk using the finite element method with the hardening soil model. The calibration results are summarized using a correction factor, η, which is defined as the ratio of pk_FEM to pk_MSD. It is shown that η is correlated to some input parameters. If this correlation is removed by a regression equation, f, the modified solution f(pk_MSD) agrees very well with pk_FEM. Although in reality the mobilized soil strength varies with principal stress direction, it is found that a simple average of plane strain compression and extension results is sufficient to produce the above agreement. The proposed nonlinear pk–ur curve is applied to an actual tunnel lining design example. The predicted tunnel deformations agree very well with the measured data. In contrast, a linear pk model would produce an underestimation of tunnel convergence and internal forces by 2–4 times due to the overestimation of pk at a large strain level.

scholarly journals Approach for Optimisation of Tunnel Lining Design

2020 ◽  
Vol 10 (19) ◽  
pp. 6705
Author(s):  
Marek Mohyla ◽  
Karel Vojtasik ◽  
Eva Hrubesova ◽  
Martin Stolarik ◽  
Jan Nedoma ◽  
...  
Keyword(s):  
Rock Mass ◽  
Numerical Models ◽  
Tunnel Lining ◽  
Time Dependent ◽  
Design Element ◽  
Heterogeneous Structure ◽  
Underground Engineering ◽  
Software Application ◽  
Tunnel Lining Design ◽  
Dependent Property

This paper presents an approach that enables the specific characteristics of a primary tunnel lining implemented using numerical modelling to be taken into account during its design. According to the fundamental principles of the New Austrian Tunnelling Method, the primary lining undergoes time-dependent deformation, which is determined by its design. The main design element is shotcrete, which, shortly after its application, interacts with the surrounding rock mass and steel arch frame. The primary lining ensures the equilibrium stress–strain state of “rock mass–tunnel lining” during excavation. The structural interaction varies depending on the hardening of the shotcrete, the rheological properties of the rock mass, and other factors. The proposed approach uses the Homogenisation software application, which was developed by the Faculty of Civil Engineering at the Department of Geotechnics and Underground Engineering of the VSB—Technical University of Ostrava. This software allows the heterogeneous structure of the lining to be considered by replacing it with a homogenous structure. The parameters of the homogeneous primary lining, which take into account the steel reinforcement elements and the time-dependent property of the shotcrete, are included in numerical models.

scholarly journals Development of a user-friendly regression model to evaluate carbon emissions of office buildings design in the subtropics

Facilities ◽  
2019 ◽  
Vol 37 (11/12) ◽  
pp. 860-878
Author(s):  
Pan Lee ◽  
Edwin H.W. Chan ◽  
Queena K. Qian ◽  
Patrick T.I. Lam
Keyword(s):  
Regression Model ◽  
Carbon Emissions ◽  
Building Design ◽  
Office Buildings ◽  
Design Parameters ◽  
Design Teams ◽  
Content Type ◽  
High Rise ◽  
User Friendly ◽  
Influential Parameters

Purpose Design teams have difficulties in assessing building carbon emissions at an early stage, as most building energy simulation tools require a detailed input of building design for estimation. The purpose of this paper is to develop a user-friendly regression model to estimate carbon emissions of the preliminary design of office buildings in the subtropics by way of example. Five sets of building design parameters, including building configuration, building envelope, design space conditions, building system configuration and occupant behaviour, are considered in this study. Design/methodology/approach Both EnergyPlus and Monte Carlo simulation were used to predict carbon emissions for different combinations of the design parameters. A total of 100,000 simulations were conducted to ensure a full range of simulation results. Based on the simulation results, a regression model was developed to estimate carbon emissions of office buildings based on preliminary design information. Findings The results show that occupant density, annual mean occupancy rate, equipment load, lighting load and chiller coefficient of performance are the top five influential parameters affecting building carbon emissions under the subtropics. Besides, the design parameters of ten office buildings were input into this user-friendly regression model for validation. The results show that the ranking of its simulated carbon emissions for these ten buildings is consistent with the original carbon emissions ranking. Practical implications With the use of this developed regression model, design teams can not only have a simple and quick estimation of carbon emissions based on the building design information at the conceptual stage but also explore design options by understanding the level of reduction in carbon emissions if a certain building design parameter is changed. The study also provides recommendations on building design to reduce carbon emissions of office buildings. Originality/value Limited research has been conducted to date to investigate how the change of building design affects carbon emissions in the subtropics where four distinct seasons lead to significant variations of outdoor temperature and relative humidity. Previous research also did not emphasise on the impact of high-rise office building designs (e.g. small building footprint, high window-to-wall ratio) on carbon emissions. This paper adds value by identifying the influential parameters affecting carbon emissions for a high-rise office building design and allows a handy estimate of building carbon emissions under the subtropical conditions. The same approach may be used for other meteorological conditions.

SEGMENT’S JOINT IN PRECAST TUNNEL LINING DESIGN

2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Siti Norafida Jusoh ◽  
Hisham Mohamad ◽  
Aminaton Marto ◽  
Nor Zurairahetty Mohd Yunus ◽  
Fauziah Kasim
Keyword(s):  
Short Review ◽  
Joint Effect ◽  
Tunnel Lining ◽  
Ground Movement ◽  
Flexural Behaviour ◽  
Interactive Approach ◽  
Soil Stress ◽  
Tunnel Lining Design

Tunnel lining design requires an interactive approach as the design is not merely about the strength, but how much the tunnel allows to flexure to overcome the ground movement.  When tunnel interacts with soil, stress from the ground is distributed into the structure. In the case of precast segmental bolted tunnel lining, it is critical to investigate the lining joints reaction, as this affects the overall flexural behaviour of tunnel lining. The objective of this paper is to present a discussion on the mechanics response of segmental tunnel lining affected by the segment’s joint. A short review on research works conducted in recent day on joint effect in segment’s joint in tunnel lining is also presented. 

scholarly journals The Effects of Tangential Ground–Lining Interaction on Segmental Lining Behavior Using the Beam-Spring Model

2020 ◽  
Vol 10 (3) ◽  
pp. 1084 ◽  
Author(s):  
Anh The Pham ◽  
Mitsutaka Sugimoto
Keyword(s):  
Urban Areas ◽  
Earth Pressure ◽  
Tangential Direction ◽  
Tunnel Lining ◽  
Parameter Study ◽  
Shield Tunneling ◽  
Segmental Lining ◽  
Load Models ◽  
Tunneling Method ◽  
Tunnel Lining Design

The shield tunneling method is widely used, especially in urban areas, since it is efficient for minimizing disturbances to surroundings. Although segmental lining is commonly used in this method, in both the research and practice of tunnel lining design, the interaction between the ground and lining in the tangential direction remains unclear; that is, the mobilizing shear stress due to load models and the degree of the bond in the tangential direction. Therefore, to clarify the effects and mechanism of the tangential ground–lining interaction on segmental lining behavior, a parameter study was carried out, taking tangential spring stiffness, load models, soil stiffness, and shallow and deep tunnels as parameters. The interaction conditions were based on the existing literature. It was found that (1) the tangential spring has small effects on lining behavior, (2) the load model significantly affects the sectional forces, (3) the initial tangential earth pressure and slip ground–lining boundary provide more safety from a design viewpoint, and (4) in the case of shallow tunnels in soft ground, tensile stress appears in the lining. Therefore, it is important to take the tangential ground–lining interaction conditions into consideration during tunnel lining analysis.

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